"The new-type ballistic missile was fired in vertical mode" on Wednesday in the waters off Wonsan Bay, the Korean Central News Agency reported.

It identified the SLBM as a Pukguksong-3.

The North's leader Kim Jong Un sent "warm congratulations" to research units involved in the launch, which "had no adverse impact on the security of neighboring countries," KCNA said.

North Korea is banned from ballistic missile launches by United Nations Security Council resolutions, and Tokyo said earlier that a part of the missile landed in waters within Japan's exclusive economic zone.

The test-firing "ushered in a new phase in containing the outside forces' threat to the DPRK and further bolstering its military muscle for self-defence," KCNA said, using a formal acronym for the North.